The chemical structure, synthesis and assembly of the membrane proteins of vesicular stomatitis virus (VSV) will be studied. The major objectives of this proposed research are to correlate structure-function relationship of the VS viral glycoprotein and to determine the factors involved in the attachment of VSV to host cell surfaces. The VS viral glycoprotein has been shown to be the most important viral determinant in cell attachment and antigenicity. The glycoprotein will be degraded into subunits so that the protein and carbohydrate moieties can be studied particularly as they relate to the attachment process and immunological reactivity. Concomitantly, overlapping peptides will be produced by cyanogen bromide and trypsin digestion so that the $ structure of the VS viral glycoprotein can be elucidated. The effect of host cell modification of the VS viral glycoprotein as a possible mechanism for regulating viral virulence will be investigated. We also plan to determine the structure of the nonglycosylated viral matrix protein by analysis of amino acid composition and tryptic and cyanogen bromide peptide mapping. A second objective is to study the glycosylated membrane proteins of the RNA tumor virus, mouse mammary tumor virus (MuMTV). We plan to elucidate and compare the chemical structure of individual MuMTV glycoproteins. Studies of the role of the glycoproteins in the attachment of MuMTV to host cells will be conducted utilizing in vivo and in vitro produced pseudotypes of MuMTV and VSV, as well as liposomes in which glycoproteins are inserted.